The present invention relates generally to the control of a defrost heater for a refrigerator and specifically to an adaptive control method and apparatus therefor.
It is known to provide a defrost heater to a refrigeration unit such as in a domestic refrigerator or freezer appliance. In conventional arrangements, the heater is cycled on the basis of electromechanical timers which accumulate time on the basis of compressor run time. When the timer accumulates a predetermined amount of compressor run time, the defrost heater initiates a defrost cycle, regardless of the current state of various refrigeration components and environment. This can lead to an inefficient use of energy.
The present invention provides a method for defrosting a household refrigeration appliance including a compressor and a refrigeration compartment having a door. Said method comprises the steps of: waiting for a defrost interval (X) based on accumulated compressor run time; initiating a defrost cycle only after both the defrost interval has elapsed and the compressor is not running; and after initiating said defrost cycle, terminating said defrost cycle as determined by a defrost termination thermostat.
The present invention further provides a defrosting refrigerator, comprising: a cooling apparatus for providing cooling air to the refrigerator when operating; a defrost apparatus which operates upon initiation for a defrost period; and a controller which initiates the defrost apparatus after a set defrost interval elapses and only when the cooling apparatus is not operating.
The present invention further provides a method for defrosting a household refrigeration appliance comprising the steps of: providing a control means for controlling a defrost means of the appliance; initiating a defrost cycle after a defrost interval has elapsed; adjusting the defrost interval of the control means to a vacation defrost interval, which is greater than a maximum normal defrost interval, if a door of the appliance has not been opened for a predetermined period; and resetting the defrost interval of the control means to equal or less than the maximum normal defrost interval from the vacation defrost interval when the door is opened.
The present invention further provides a defrosting refrigerator comprising: a defrost apparatus; at least one compartment having a door, the door having a sensor for detecting the open or closed condition of the door; and a controller which monitors the sensor, which initially controls the defrost apparatus according to a first mode, and which controls defrost apparatus according to a second mode when the sensor indicates the door has been closed for a predetermined period, wherein the controller reverts to the first mode if the sensor indicates the